[c-nsp] BGP Multihoming and syncronous traffic flow for the different traffic types

[Burak Dikici]

  P2P is peer to peer traffic. Peer to peer traffic to the outside of the
country , it will go over the ISP-2 link , and the return traffic of this
connection will come back through the same ISP-2 link.
  My clients are using the real ip addresses. If i advertise their subnet
from the ISP-1 with BGP to the outside world , the outside world knows them
via the ISP-1 link and the their return traffic will come through the ISP-1
link.
  I catch the outside of the country with p2p traffic with NBAR and route
this traffic to the ISP-2 with PBR , what about the return traffic of this
connection ? At this point the NATing comes in the play. The outside of the
country with p2p traffic's source ip address will be NATed to the ISP-2 NAT
pool addresses. And this NAT pool addresses will be advertise with BGP only
to the ISP-2 link. Therefore , the outside world knows this addresses only
through the ISP-2 and the return traffic of this connection will come back
through the ISP-2 link , it is symmetrical traffic flow for the outside of
the country with p2p traffic. Am i right ?

How can it be done without using the NAT ?
Regards...





On Sat, Apr 11, 2009 at 1:55 AM, Burak Dikici <bdikici at gmail.com> wrote:

> ISP-1
> ISP-2
> same country ISP               outside of country ISP
> |                                                      |
> |                                                      |
> |                                                      |
> |                                                      |
> |                                                      |
> |                                                      |
> |                                                      |
> |                                                      |
> ----------     My router (Cisco 7600)--------
>                               |
>                               |
>                               |
> User's real subnet (for example 50.50.0.0)
>
>
>
> Hello ,
>
> I have got two different ISPs connections from my router. One of the ISP is
> in my country (local ISP) , other IPS is in the different country. Here are
> the requiremets ;
>
> If the traffic is p2p and if it goes to the outside of the country , use
> ISP-2. And the return of this traffic will come from the ISP-2 link.
> (syncronous traffic flow)
>
> The other traffic types will use the ISP-1 connection. For example , maybe
> p2p traffic goes inside of the country. Use ISP-1 connection for this type
> of traffic as well.
>
> How can i differentiate the traffic goes to the inside of the country , or
> the outside of the country ?
>
> The users have got real ip addresses. (Nearly 10.000 users.) To catch the
> p2p traffic , i think we have to use NBAR. To route the different kind of
> traffic types , i think we have to use PBR. For this kind of request , i can
> use NATing on the ISP-2 link. But , is this cause any problem for this type
> of connection on the Cisco 7600 model router ? Is NAT doing on the Cisco
> 7600 router by software based or hardware based ? For complete scenario , we
> have to use NAT , PBR and NBAR. Is that cause any problem on the Cisco 7600
> router , what about performance ? Could you give me an idea how can it be
> done ? Kind Regards...
>
> Burak Dikici